Night fell before the rescue party reached Palo Duro. The caÑon was at that time a terra incognita to these cattlemen of the Panhandle. To attempt to explore it in the darkness would be to court disaster. The Apaches might trap the whole party.

But neither the Ranger nor Wadley could endure the thought of waiting till morning to push forward. The anxiety that weighed on them both could find relief only in action.

Jack made a proposal to Ramona's father. "We've got to throw off and camp here. No two ways about that. But I'm goin' to ride forward to Palo Duro an' see what I can find out. Want to go along?"

"Boy, I had in mind that very thing. We'll leave Jumbo in charge of the camp with orders to get started soon as he can see in the mo'nin'."

The two men rode into the darkness. They knew the general direction of Palo Duro and were both plainsmen enough to follow a straight course even in the blackest night. They traveled at a fast road gait, letting the horses pick their own way through the mesquite. Presently a star came out—and another. Banked clouds scudded across the sky in squadrons.

At last, below their feet, lay the great earth rift that made Palo Duro. It stretched before them an impenetrable black gulf of silence.

"No use trying to go down at random," said Jack, peering into its bottomless deeps. "Even if we didn't break our necks we'd get lost down there. My notion is for me to follow the bank in one direction an' for you to take the other. We might hear something."

"Sounds reasonable," agreed Wadley.

The cattleman turned to the left, the Ranger to the right. Roberts rode at a slow trot, stopping every few minutes to listen for any noise that might rise from the gulch.

His mind was full of pictures of the girl, one following another inconsequently. They stabbed him poignantly. He had a white dream of her moving down the street at Tascosa with step elastic, the sun sparkling in her soft, wavy hair. Another memory jumped to the fore of her on the stage, avoiding with shy distress the advances of the salesman he had jolted into his place. He saw her grave and gay, sweet and candid and sincere, but always just emerging with innocent radiance from the chrysalis of childhood.

Her presence was so near, she was so intimately close, that more than once he pulled up under an impression that she was calling him.

It was while he was waiting so, his weight resting easily in the saddle, that out of the night there came to him a faint, far-away cry of dreadful agony. The sound of it shook Jack to the soul. Cold beads of perspiration stood out on his forehead. Gooseflesh ran down his spine. His hand trembled. The heart inside his ribs was a heavy weight of ice. Though he had never heard it before, the Ranger knew that awful cry for the scream of a man in torment. The Apaches were torturing a captured prisoner.

If Dinsmore had been captured by them the chances were that 'Mona had been taken, too, unless he had given her the horse and remained to hold the savages back.

Roberts galloped wildly along the edge of the rift. Once again he heard that long-drawn wail of anguish and pulled up his horse to listen, the while he shook like a man with a heavy chill.

Before the sound of it had died away a shot echoed up the caÑon to him. His heart seemed to give an answering lift of relief. Some one was still holding the Apaches at bay. He fired at once as a message that help was on the way.

His trained ear told him that the rifle had been fired scarcely a hundred yards below him, apparently from some ledge of the cliff well up from the bottom of the gulch. It might have come from the defenders or it might have been a shot fired by an Apache. Jack determined to find out.

He unfastened the tientos of his saddle which held the lariat. A scrub oak jutted up from the edge of the cliff and to this he tied securely one end of the rope. Rifle in hand, he worked over the edge and lowered himself foot by foot. The rope spun round like a thing alive, bumped him against the rock wall, twisted in the other direction, and rubbed his face against the harsh stone. He had no assurance that the lariat would reach to the foot of the cliff, and as he went jerkily down, hand under hand, he knew that at any moment he might come to the end of it and be dashed against the boulders below.

His foot touched loose rubble, and he could see that the face of the precipice was rooted here in a slope that led down steeply to another wall. The ledge was like a roof pitched at an extremely acute angle. He had to get down on hands and knees to keep from sliding to the edge of the second precipice. At every movement he started small avalanches of stone and dirt. He crept forward with the utmost caution, dragging the rifle by his side.

A shot rang out scarcely fifty yards from him, fired from the same ledge upon which he was crawling.

Had that shot been fired by an Apache or by those whom he had come to aid?